CN111862594A

CN111862594A - Method, device and storage medium for identifying weak unit in road traffic network

Info

Publication number: CN111862594A
Application number: CN202010502544.3A
Authority: CN
Inventors: 田建辉; 许项东; 刘冰; 经维维; 李军; 江金寿; 叶金华; 王晓悦; 陈科; 何圣华
Original assignee: Ordnance Science and Research Academy of China
Current assignee: Ordnance Science and Research Academy of China
Priority date: 2020-06-04
Filing date: 2020-06-04
Publication date: 2020-10-30
Anticipated expiration: 2040-06-04
Also published as: CN111862594B

Abstract

The application provides a method, a device and a storage medium for identifying weak units in a road traffic network, relates to the technical field of traffic, and is used for identifying weak units in the road traffic network. The method comprises the following steps: extracting each traffic unit in a road traffic network, wherein the traffic unit comprises nodes in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying connecting edges of the connecting nodes, and the nodes represent end points of the road or intersections of the road; determining a network connectivity value for each traffic unit, the network connectivity value being determined by identifying a pair of disconnected nodes caused by failure of each traffic unit; and identifying weak units in the traffic units according to the network connectivity value and the connectivity value threshold of each traffic unit. According to the method, the influence degree of each traffic unit on the road traffic network is determined according to the information of the node pair which is not communicated due to the failure of each traffic unit, and then weak units with high influence on the road traffic network are identified.

Description

Method, device and storage medium for identifying weak unit in road traffic network

Technical Field

The present application relates to the field of traffic technologies, and in particular, to a method, an apparatus, and a storage medium for identifying a weak unit in a road traffic network.

Background

The urban road traffic system is the basis of an important life line system and social and economic activities of a city; road traffic networks are created based on urban traffic systems, the efficient operation of which supports the efficient operation of cities. However, the road traffic network is objective and vulnerable, and some weak units exist in the network, and if the weak units are attacked and fail, the connectivity of the road traffic network can be seriously affected, so that the normal operation of a city is affected, and therefore, how to identify the weak units in the road traffic network is a problem to be considered.

Disclosure of Invention

The embodiment of the application provides a method, a device and a storage medium for identifying a weak unit in a road traffic network, which are used for identifying the weak unit in the road traffic network.

In a first aspect of the present application, a method for identifying a weak cell in a road traffic network is provided, including:

extracting each traffic unit in a road traffic network by setting a communication interface, wherein the traffic unit comprises a node in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying a connecting edge connecting the node, and the node represents an end point of a road or an intersection of at least two roads;

Determining a network connectivity value for each of the traffic elements, the network connectivity value determined by identifying a pair of nodes that are disconnected due to failure of each of the traffic elements; the node pair comprises a set of any two nodes of a traffic path in the road traffic network;

and identifying weak units in the traffic units according to the network connectivity value and the connectivity value threshold of each traffic unit, wherein the weak units comprise traffic units with high influence on the connectivity degree of the road traffic network.

In one possible implementation manner, the method further includes:

determining the degree of vulnerability of the road traffic network according to at least one of the number of the identified weak cells and the communication influence value of the weak cells on the road traffic network; the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the weak cell failure and information of a node pair which is not connected.

In one possible implementation, the traffic unit includes nodes in the road traffic network and K road elements in a traffic path, where K is a positive integer greater than 1, and further includes:

If the traffic unit fails, acquiring at least one parameter value of a network connection value and a connection influence value of each road element in the traffic unit, wherein the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the failure of each road element and information of a node pair which is not connected;

and determining a recovery sequence for recovering the road elements in the traffic units in the road traffic network according to the acquired at least one parameter value of each road element in the traffic units.

In a possible implementation manner, the determining, according to the obtained at least one parameter value of each road element in the traffic unit, a recovery sequence for recovering each road element in the traffic unit in the road traffic network includes:

if one parameter value of each road element in the traffic unit is obtained, sorting each road element in the traffic unit according to the size of the parameter value; otherwise, sorting the road elements in the traffic unit according to the priority of each parameter value in the at least one parameter value and the size of the parameter value;

And determining the sequence of the road elements in the traffic units after sequencing as a recovery sequence for recovering the road elements in the traffic units in the road traffic network.

In a possible implementation manner, obtaining a parameter value of each road element in the traffic unit, and determining a recovery sequence for recovering each road element in the traffic unit in the road traffic network according to the obtained at least one parameter value of each road element in the traffic unit includes:

determining, for the K road elements in the traffic unit, a restoration order of each of the K road elements by a multi-round restoration order determination process, wherein the i-th round restoration order determination process includes the processes of step S1 to step S4, where i is a positive integer smaller than K:

step S1: performing simulation recovery on the road elements with the determined recovery sequence in the K road elements in the road traffic network;

step S2: determining the parameter value of the road element with the undetermined recovery sequence in the K road elements based on the road traffic network subjected to simulation recovery;

Step S3: according to the sequence of the parameter values from large to small, sorting the road elements of which the recovery sequence is not determined in the K road elements;

step S4: and determining the recovery sequence of the road elements which are sequenced in the first sequence in the sequenced road elements as the ith recovery in the K road elements.

In a possible implementation manner, obtaining two parameter values of each road element in the traffic unit, where the two parameter values include the network connectivity value and the connectivity influence value, and determining, according to the obtained at least one parameter value of each road element in the traffic unit, a recovery order for recovering each road element in the traffic unit in the road traffic network includes:

determining, for the K road elements in the traffic unit, a restoration order of each of the K road elements by a multi-round restoration order determination process, wherein a j-th round restoration order determination process includes the processes of step S11 to step S14, where j is a positive integer smaller than K:

step S11: performing simulation recovery on the road elements with the determined recovery sequence in the K road elements in the road traffic network;

Step S12: determining the two parameter values of the road elements of which the recovery sequence is not determined in the K road elements based on the road traffic network subjected to simulation recovery;

step S13: according to the sequence of the parameter value with high priority in the two parameter values from large to small, the road elements of the K road elements, of which the recovery sequence is not determined, are sorted for the first time;

step S14: determining the recovery sequence of the road elements which are sorted in the first sequence and are unique in the road elements sorted for the first time as the jth recovery of the K road elements; if the road elements sorted in the first sequence in the road elements sorted in the first sequence comprise at least two road elements, sorting the at least two road elements for the second time according to the sequence of the parameter values with low priority from large to small in the two parameter values, and determining the recovery sequence of the road elements sorted in the first sequence in the road elements sorted in the second time as the jth recovery in the K road elements.

In a possible implementation manner, the network connectivity value is a ratio of the number of the node pairs connected in the road traffic network to the total number of the node pairs in the road traffic network after each traffic unit fails, and the weak unit is a traffic unit of which the network connectivity value is smaller than a first connectivity value threshold; or

The network connection value is the ratio of the number of the disconnected node pairs in the road traffic network to the total number of the node pairs in the road traffic network after each traffic unit fails, and the weak unit is a traffic unit of which the network connection value is smaller than a second connection threshold value.

In one possible implementation, the network efficiency includes an average of reference path values of a node pair in the road traffic network, the reference path value being an inverse of a shortest transit path length between two nodes in the node pair.

In one possible implementation, the information of the disconnected node pair includes one or more of the following information:

the number of connected nodes is not the same as the number of connected nodes; the pedestrian passing frequency ratio is determined according to cell information of a preset traffic cell to which a first node and a second node belong, the cell information comprises the geographic area, population density and number of people going out of the preset traffic cell, and the first node and the second node are nodes in the disconnected node pair;

spatial distribution information of disconnected node pairs.

In a second aspect of the present application, there is provided an apparatus for identifying a weak cell in a road traffic network, comprising:

The traffic unit acquisition unit is used for extracting each traffic unit in a road traffic network by setting a communication interface, wherein each traffic unit comprises a node in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying a connecting edge connecting the nodes, and the nodes represent end points of roads or intersections of at least two roads;

a network connectivity value determination unit for determining a network connectivity value for each of the traffic units, the network connectivity value being determined by identifying a pair of nodes that are disconnected due to failure of each of the traffic units; the node pair comprises a set of any two nodes of a traffic path in the road traffic network;

and the weak unit identification unit is used for identifying weak units in the traffic units according to the network communication value and the communication value threshold of each traffic unit, wherein the weak units comprise traffic units with high influence on the communication degree of the road traffic network.

In one possible implementation, the apparatus further includes:

the network vulnerability determining unit is used for determining the vulnerability of the road traffic network according to at least one information of the number of the identified weak units and the communication influence value of the weak units on the road traffic network; the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the weak cell failure and information of a node pair which is not connected.

In one possible implementation, the traffic unit includes nodes in the road traffic network and K road elements in a traffic path, K being a positive integer greater than 1, the apparatus further including:

the network recovery unit is used for acquiring at least one parameter value of a network connection value and a connection influence value of each road element in the traffic unit if the traffic unit fails, wherein the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the failure of each road element and information of a node pair which is not connected;

In a possible implementation manner, the network recovery unit is specifically configured to:

In a possible implementation manner, the network recovery unit is specifically configured to obtain one parameter value of each road element in the traffic unit, and determine, for the K road elements in the traffic unit, a recovery order of each road element in the K road elements through the following multiple rounds of recovery order determination processes, where the i-th round of recovery order determination process includes the following processes from step S1 to step S4, and i is a positive integer smaller than K:

In a possible implementation manner, the network recovery unit is specifically configured to obtain two parameter values of each road element in the traffic unit, and determine, for the K road elements in the traffic unit, a recovery order of each road element in the K road elements through the following multiple rounds of recovery order determination processes, where the j-th round of recovery order determination process includes the following processes from step S11 to step S14, and j is a positive integer smaller than K:

In one possible implementation, the network efficiency includes an average of reference path values of a node pair in the road traffic network, the reference path value being an inverse of a shortest transit path between two nodes in the node pair.

Spatial distribution information of disconnected node pairs.

In a third aspect of the present application, there is provided a computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, the processor implementing the method of the first aspect and any one of the possible embodiments when executing the program.

In a fourth aspect of the present application, a computer-readable storage medium is provided, which stores computer instructions that, when executed on a computer, cause the computer to perform the method according to the first aspect and any one of the possible embodiments.

Due to the adoption of the technical scheme, the embodiment of the application has at least the following technical effects:

according to the embodiment of the application, the influence of each traffic unit on the communication degree of the road traffic network is determined according to the information of the node pair which is not communicated in the road traffic network and is caused by the failure of each traffic unit, and then the weak unit with high influence on the communication degree of the road traffic network is identified.

Drawings

Fig. 1 is a schematic flowchart illustrating a process of identifying a weak element in a road traffic network according to an embodiment of the present application;

Fig. 2 is an exemplary diagram of a topology of a road traffic network according to an embodiment of the present application;

fig. 3 is a schematic diagram of a traffic path between nodes according to an embodiment of the present disclosure;

FIG. 4 is a schematic illustration of the impact of a traffic unit failure according to an embodiment of the present disclosure;

FIG. 5 is a schematic diagram illustrating a simulation effect of determining a network connectivity value of a traffic unit according to an embodiment of the present application;

FIG. 6 is a schematic diagram of another simulation effect for determining a network connectivity value of a traffic unit according to an embodiment of the present application;

fig. 7 is a schematic diagram illustrating a simulation effect of a change value of network efficiency caused by failure of each traffic unit according to an embodiment of the present application;

FIG. 8 is a schematic diagram illustrating spatial distribution information of disconnected node pairs according to an embodiment of the present application;

fig. 9 is a schematic diagram of a recovery order determination process provided in an embodiment of the present application;

fig. 10 is a schematic diagram of another recovery order determination process provided in an embodiment of the present application;

fig. 11 is a schematic diagram illustrating an attack on a traffic unit including a plurality of road elements according to an embodiment of the present application;

fig. 12 is a schematic diagram of a recovery sequence for recovering a plurality of road elements in a traffic unit in a road traffic network according to an embodiment of the present application;

Fig. 13 is a block diagram of an apparatus for identifying a weak element in a road traffic network according to an embodiment of the present disclosure;

fig. 14 is a block diagram of a computer device according to an embodiment of the present application.

Detailed Description

In order to better understand the technical solutions provided by the embodiments of the present application, the following detailed description is made with reference to the drawings and specific embodiments.

In order to facilitate those skilled in the art to better understand the technical solutions of the present application, the following description refers to the technical terms of the present application.

Road traffic network: the network topology structure can be created according to an actual urban traffic system, wherein the end points of a real road and intersections of different roads are regarded as nodes, the end points of the real road and the road sections between the intersections of different roads are regarded as connecting edges connecting the nodes, and the network topology structure constructed by the network topology structure is the road traffic network in the embodiment of the application.

And (3) road elements: nodes in a road traffic network or connecting edges between different nodes form a passing path.

A traffic unit: a unit comprising nodes in a road traffic network and at least one road element in a transit path, such as a traffic unit may, but not exclusively, comprise the following road elements: a node, a plurality of nodes, a communication path, a plurality of transit paths, at least one node and at least one transit path, and the like.

The following explains the concept of the present application.

Road traffic networks are created based on urban traffic systems, the efficient operation of which supports the efficient operation of cities. However, the road traffic network has objectivity and vulnerability, some weak units exist in the network,

in case of an accident, after the road traffic network is attacked or weak units therein are attacked, many traffic paths in the road traffic network are blocked, so that the road traffic network is paralyzed in a large area, and the urban traffic is seriously affected today.

In view of this, the inventor designs a method, an apparatus, and a storage medium for identifying weak cells in a road traffic network, in which after traffic cells in the road traffic network are acquired, network connectivity values of the traffic cells are determined according to node pairs that are not connected in the road traffic network and are caused by failure of the traffic cells, and then weak cells that have a high influence on the connectivity degree of road traffic in the traffic cells are identified according to the network connectivity values and the connectivity threshold values of the traffic cells, wherein:

The method provided by the embodiment of the application is described in detail below with reference to the accompanying drawings.

Referring to fig. 1, an embodiment of the present application provides a method for identifying a weak element in a road traffic network, which specifically includes the following steps:

step S101, extracting a network connectivity value of each traffic unit in a road traffic network by setting a communication interface, wherein the traffic unit comprises nodes in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying connecting edges of the connecting nodes, and the nodes represent end points of the road or intersections of at least two roads.

The communication interface is not limited, and may be a communication interface commonly used in the computer field.

As an example, before step S101, a topology structure of a road traffic network may be created according to an actual traffic condition, where the road traffic network includes a plurality of nodes and connecting edges connecting the nodes, where each node is used to represent an end point of an actual road or an intersection of different roads, and the connecting edges represent links between different nodes, as shown in fig. 2, a schematic diagram of a topology structure of a road traffic network is shown, where numerals 1 to 58 represent 58 nodes, and the connecting edges between the nodes represent links, and in an actual situation, the links are directional, i.e., point from one node to another node, and each connecting edge in fig. 2 represents two opposite unidirectional links, so that 74 edges in the diagram actually represent 148 unidirectional links.

The transit path may be a certain unidirectional link represented by an edge between two nodes, and the length of the link is not infinite, such as a first link 301 represented by a directional link from the node 41 to the node 47 in fig. 3, or a second link 302 represented by a directional link from the node 42 to the node 51; the passing path may also be a path composed of end-to-end unidirectional road segments represented by a plurality of edges and having a length that is not infinite, such as a path composed of the first road segment 301 and a third road segment starting from the node 47 and pointing to the node 57 in fig. 3; regarding a path with length not being infinite length between two nodes as a passing path between the two nodes, regarding the path with length being infinite length between the two nodes as a passing path between the two nodes; if the lengths of all paths between two nodes are infinite, it is considered that no traffic path exists between the two nodes.

Step S102, determining the extracted network connection value of each traffic unit, wherein the network connection value is determined by identifying the disconnected node pair caused by the failure of each traffic unit; the node pair comprises a set formed by any two nodes of a passing path in the road traffic network;

In the embodiment of the application, the network connection value of each traffic unit can be determined according to the number of unconnected node pairs or the relationship between the number of connected node pairs and the total number of node pairs in the road traffic network after each traffic unit fails.

The failure of a traffic unit may be understood as that the length of a road segment directly connected to each node in the traffic unit is infinite, and the length of each passing path in the traffic unit is infinite.

And S103, identifying weak units in the extracted traffic units according to the network connectivity value and the connectivity value threshold of each traffic unit, wherein the weak units comprise traffic units with high influence on the connectivity degree of the road traffic network.

Because the weak unit has high influence on the communication degree of the road traffic network, after the weak unit fails, the large-area paralysis of the road traffic network is possibly caused, and therefore after the weak unit is identified, the protection on the weak unit can be enhanced according to the actual condition, or when the road traffic network is attacked, the communication of the weak unit is preferentially recovered, and the communication of each node in the road traffic network is further ensured to the maximum degree.

In the following, the traffic units in the embodiments of the present application are described in detail, and one traffic unit may include at least one road element in a node and a traffic path in a road traffic network, that is, one traffic unit may include, but is not limited to, the following cases:

1) A traffic element comprising a node or a transit path

Since a communication path may include a road segment or a plurality of road segments, a traffic unit may include a node, a road segment or a plurality of road segments; with continued reference to fig. 3, the node 41 or the node 47 may be regarded as a traffic unit, the first road segment 301 may be regarded as a traffic unit, or a traffic route formed by the first road segment 301 and the third road segment 303 may be regarded as a traffic unit.

2) One traffic unit comprises a plurality of nodes or a plurality of traffic paths

Since a communication path may include one road segment or a plurality of road segments, one traffic unit may include a plurality of nodes or a plurality of road segments; with continued reference to fig. 3, the network area formed by the node 41, the node 42, the node 47 and the node 51 may be used as a traffic unit; the network area formed by two traffic paths, the first road section 301 and the second road section 302, can also be used as a traffic unit.

3) A traffic unit comprises at least one node and at least one traffic route

Since a communication path may include a road segment or a plurality of road segments, a traffic unit may include at least one node and at least one road segment; with continued reference to fig. 3, a network region composed of the node 41, the node 47, the node 42, the first road segment 301 and the second road segment 302 may be regarded as a traffic unit.

The following describes the node pairs in the embodiments of the present application:

the node pairs comprise a set formed by any two nodes of a traffic path before the traffic unit in the road traffic network fails.

In the embodiment of the present application, the node pair may be non-directional, please continue to refer to fig. 2, and there is a connecting edge between the node 41 and the node 47, that is, the node 41 and the node 47 form a node pair (41, 47).

In the embodiment of the present application, a node pair may also have a direction, and the direction of the node pair may be determined by the direction of the transit path, for example, referring to fig. 3 again, if a first transit path composed of the first segment 301 exists between the node 41 and the node 47, and the direction of the transit path points from the node 41 to the node 47, a node pair pointing from the node 41 to the node 47 may be represented as (41, 47), where the direction of the node pair in the node pair (41, 47) is from the node 41 to the node 47; if a second transit path composed of the second route segment 302 exists between the node 41 and the node 42, the node pair pointing from the node 41 to the node 42 may be represented as (41, 42); a third traffic path exists between node 41 and node 57, which is comprised of first segment 301 and third segment 303, and node 41 and node 57 form a node pair (41, 57) that points from node 41 to node 57.

The following describes the case of traffic unit failure in the embodiment of the present application:

in the embodiment of the present application, a traffic unit may fail after encountering a designated attack, and after a traffic unit fails, if the traffic unit includes a node, the case after the traffic unit fails includes assuming that the length of a road segment directly connected to each node in the traffic unit is infinite, or setting a road segment directly connected to each node in the traffic unit as a no-go communication state, please continue referring to fig. 3, and if a traffic unit including a node 41 fails, setting the lengths of road segments directly connected to the node 41, such as a road segment between the node 41 and the node 47 and a road segment between the node 41 and the node 42, as infinite, or setting the two road segments as a no-go state;

if the traffic unit includes a traffic route (one traffic route may include one road segment or a plurality of road segments), the failure of the traffic unit includes assuming that the length of the traffic route is infinite, please continue to refer to fig. 3, and if the traffic unit including the second traffic route between the node 41 and the node 42 and the third traffic route between the node 41 and the node 57 fails, the length of the second traffic route is set to be infinite, and the length of the third traffic route is also set to be infinite.

The designated attacks encountered by the traffic units can be, but are not limited to, that the road surfaces of the traffic units are intentionally damaged, the traffic units fail to pass, the traffic units are enclosed by certain people and cannot pass, the traffic units are constructed and temporarily prohibited to pass, or the traffic units stop passing temporarily due to traffic accidents, and the like.

The following describes the connected node pairs and the disconnected node pairs in the embodiment of the present application in detail:

the connected node pairs refer to node pairs of a traffic path with length which is not infinite after a certain traffic unit fails; the node pair which is not connected refers to the node pair with the shortest passing path between two nodes being infinite length after a certain traffic unit fails.

Specifically, after a certain traffic unit fails, the length of a road segment directly connected with the traffic unit is set to infinity, and further, the shortest passing path between two nodes of a node pair can be calculated according to a Floyd shortest path algorithm; if the length of the shortest traffic path between two nodes of a node pair is infinite, the node pair is regarded as a disconnected node pair, and if the length of the shortest traffic path between two nodes of a node pair is not infinite, the node pair is regarded as a connected node pair.

For ease of understanding, some examples are given herein, and referring to fig. 4, if the node 41 is used as a traffic unit, the upper graph in fig. 4 is a partial topology of the road traffic network before the node 41 fails, and it can be seen that at least the following node pairs exist in the road traffic network: node pair (41, 47), node pair (41, 42), node pair (41, 51), node pair (41, 48), node pair (41, 54), node pair (43, 48), node pair (47, 49), node pair (44, 16), etc.; the lower graph in fig. 4 is a partial topology structure of the road traffic network after the node 41 fails, and it can be seen that, after the node 41 fails, the length of the link between the node 41 and the node 47 is infinite (i.e., disconnected), and the length of the link between the node 41 and the node 42 is infinite (i.e., disconnected), and then the length of the shortest traffic path between two nodes in the node pair (41, 47), the node pair (41, 42), the node pair (41, 51), the node pair (41, 48), and the node pair (41, 54) is infinite, so that the node pair (41, 47), the node pair (41, 42), the node pair (41, 51), the node pair (41, 48), and the node pair (41, 54) are disconnected after the node 41 fails; when the node 41 fails, the length of the shortest transit path between two nodes of the node pair (43, 48), the node pair (47, 49), and the node pair (44, 16) is not infinite, and thus the node pair (43, 48), the node pair (47, 49), and the node pair (44, 16) are connected after the node 41 fails.

As an example, the network connectivity value in step S102 may be, but is not limited to, the following two cases:

first network connectivity value: the network connectivity value is a ratio of the number of the connected node pairs in the road traffic network to the total number of the node pairs in the road traffic network after the traffic unit fails.

Specifically, the network connectivity value of any one traffic cell may be determined by the following equation 1.

Equation 1:

in equation 1, P1 is the network connectivity value for a traffic cell, N1 is the number of connected node pairs in the road traffic network after the traffic cell failure, and N2 is the total number of node pairs in the road traffic network before the traffic cell failure.

Second network connectivity value: the network connectivity value is the ratio of the number of disconnected node pairs in the road traffic network to the total number of node pairs in the road traffic network after each traffic unit fails.

Specifically, the network connectivity value of any one traffic cell may be determined by the following equation 2.

Equation 2:

in formula 1, P2 is the network connectivity value of a traffic cell, N3 is the number of unconnected node pairs in the road traffic network after the traffic cell failure, and N2 is the total number of node pairs in the road traffic network before the traffic cell failure.

Further, when the network connectivity value indicates that the meanings are different, in step S103, according to the network connectivity value and the connectivity value threshold of each traffic unit, the process of identifying the weak unit in the traffic unit is also different, specifically, if the network connectivity value is a ratio of the number of the pairs of nodes connected in the road traffic network to the total number of the pairs of nodes in the road traffic network after each traffic unit fails, determining the traffic unit with the network connectivity value smaller than the first connectivity value threshold as the weak unit; and if the network connectivity value is the ratio of the number of the disconnected node pairs in the road traffic network to the total number of the node pairs in the road traffic network after the failure of each traffic unit, determining the traffic unit with the network connectivity value smaller than a second connectivity threshold value as a weak unit.

For easy understanding, a simulation effect graph of a network connectivity value is provided herein, please refer to fig. 5, in which each node is taken as a traffic unit, and the network connectivity value is a ratio of the number of disconnected node pairs to the total number of the node pairs after the traffic unit fails; in the figure, numerals 1 to 58 represent the identifiers of nodes, and the size of the circle of each node represents the size of the network connectivity value corresponding to the node, from which it can be seen that the network connectivity values of the

nodes

3 and 8 are larger, and the network connectivity values of other nodes are smaller, so that the

nodes

3 and 8 are identified weak units.

For easy understanding, another simulation effect graph of the network connectivity value is given here, please refer to fig. 6, in which each road segment is taken as a traffic unit, and the network connectivity value is a ratio of the number of disconnected node pairs to the total number of road node pairs after the traffic unit fails; the numbers 1-58 in the figure represent the node identifiers, and the width of each segment represents the magnitude of the network connectivity value corresponding to the segment, from which it can be seen that the network connectivity values of the segments between the node 3 and the node 19 and between the node 19 and the node 8 are larger, and the network connectivity values of the other segments are smaller, so that the segments between the node 3 and the node 19 and between the node 19 and the node 8 are identified weak units.

As an embodiment, after step S103, the vulnerability of the road traffic network may also be determined according to the information of the identified weak cell, but not limited to, by any of the following ways:

the first network vulnerability degree determining method comprises the following steps:

the vulnerability of the road traffic network is determined based on the number of identified weak cells, such as but not limited to the number of identified weak cells being determined as the vulnerability of the road traffic network.

The second network vulnerability determination method comprises the following steps:

determining the vulnerability degree of the road traffic network according to the communication influence value of the identified weak unit on the road traffic network; for example, the sum of the connection influence values of the identified weak units on the road traffic network is determined as the vulnerability of the road traffic network.

The third network vulnerability determination method:

and determining the vulnerability degree of the road traffic network according to the number of the identified weak units and the communication influence value of the identified weak units on the road traffic network.

Specifically, a sum of the communication influence values of the identified weak cells on the road traffic network may be determined, a product of the sum and the number of weak cells may be determined as the degree of weakness of the road traffic network, or a result of adding the sum and the number of weak cells may be determined as the degree of weakness of the road traffic network.

As an embodiment, the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the weak cell failure and information of a disconnected node pair.

Further, the network efficiency includes an average value of reference path values of the node pairs in the road traffic network, where the reference path value is an inverse of a shortest passing path between two nodes in the node pair.

Specifically, the above network efficiency can be obtained based on, but not limited to, the principle of the following equation 3.

Equation 3:

in formula 3, OD is a set of connected node pairs, L is a length matrix of a shortest passing path between two nodes in a node pair, and i and j are identification information of two nodes in a node pair.

For easy understanding, a simulation effect graph of a change value of network efficiency caused by failure of each traffic unit is provided, please refer to fig. 7, in which each node is taken as a traffic unit, and a network connection value is a ratio of the number of non-connected node pairs to the total number of road node pairs after the traffic unit fails; the numbers 1-58 in the graph represent the identification of nodes, wherein the height of the gray bar graph at each node represents the magnitude of the network connectivity value of the node, and the height of the black bar graph at each node represents the change value of the network efficiency caused by the node failure; the network communication values of the

nodes

3 and 8 are obviously larger, the

nodes

3 and 8 are identified weak units, the gray histograms of the failure positions of the

nodes

3 and 8 are larger in height, and the change of the network efficiency caused by the failure of the weak units can be intuitively observed to be larger.

As an embodiment, the information of the disconnected node pair includes one or more of the following information:

the number of connected nodes is not the same as the number of connected nodes; the pedestrian passing frequency ratio is determined according to cell information of a preset traffic cell to which a first node and a second node belong, the cell information comprises the geographic area, population density and number of people going out of the preset traffic cell, and the first node and the second node are nodes in the non-communicated node pair;

spatial distribution information of unconnected node pairs; in order to facilitate understanding of the spatial distribution information of the disconnected node pairs, in the embodiment of the present application, a schematic diagram is given, please refer to fig. 8, where a spatial distribution information diagram of the disconnected node pairs after the node 8 fails is given, and it can be seen that some nodes (such as the node 20, the node 58 and the node 31) are not connected to most nodes in the road traffic network.

Specifically, the pedestrian number ratio associated with the disconnected node pair may be obtained by:

firstly, for each node i generated by travel, according to the area S of a preset traffic cell where the node i is located_iMultiplied by population density d_iEstimating the total number of people in the preset traffic cell in which the node i is located, and further obtaining the number of people P who go out in the preset traffic cell in which the node i is located according to the total number of people in the preset traffic cell in which the node i is located and the average number of people going out h in the preset traffic cell _iAnd then, a logic model is introduced to calculate the traffic order ratio of the traffic from the node i to each node in the road traffic network through the following formula 4.

Equation 4:

in formula 4, P_ijFor the number of people traveling between node pairs (i, j), D_iIs the set of end points of a node pair starting from node i (the end point refers to the node pointed to by node i), P_iAnd the number of people going out of the preset traffic cell where the node i is located.

Further, after the number of trips between node pairs (i, j) obtained by the principle of formula 4, the set OD of disconnected node pairs may be based₁And calculating the pedestrian number ratio influenced by the weak unit after failure (namely the pedestrian number ratio related to the unconnected nodes influenced by the weak unit after failure) by the principle of formula 5.

Equation 5:

in equation 5, O is the set of all nodes in the road traffic network, OD₁For a set of disconnected node pairs, P_ijFor the number of people traveling between node pairs (i, j), P_iAnd the number of people going out of the preset traffic cell where the node i is located.

As an embodiment, when the traffic unit includes K road elements in the node and the passing path in the road traffic network, K is a positive integer greater than 1, that is, when the traffic unit includes a plurality of road elements, if the traffic unit fails, the reply sequence of the road elements for recovering the traffic unit in the road traffic network may also be determined as follows.

Specifically, if a certain traffic unit including a plurality of road elements fails, at least one parameter value of a network connectivity value and a connectivity influence value of each road element in the traffic unit is acquired, wherein the connectivity influence value is obtained by identifying at least one of a change value of network efficiency of the road traffic network caused by the failure of each road element and information of a node pair which is not connected;

and determining a recovery sequence for recovering the road elements in the traffic unit in the road traffic network according to the acquired at least one parameter value of each road element in the traffic unit.

Further, the recovery sequence for recovering the road elements in the traffic unit in the road traffic network may be determined according to the acquired at least one parameter value of the road elements in the traffic unit, but is not limited to any one of the following manners:

the first recovery order determination method:

in this way, only one parameter value of the network connectivity value or the connectivity influence value in each road element in the traffic unit is obtained, and then the road elements in the traffic unit can be sorted according to the obtained parameter value, and the recovery order of the road elements in the traffic unit is determined according to the sorted order of the road elements in the traffic unit.

Specifically, if the network connectivity values of the road elements of one traffic unit are obtained, the road elements in the traffic unit may be sorted according to the sequence of the network connectivity values from large to small, and the sorted sequence of the road elements in the traffic unit is determined as a recovery sequence for recovering the road elements in the traffic unit in the road traffic network;

if the connection influence value of each road element of one traffic unit is obtained, the road elements in the traffic unit can be sorted according to the sequence of the connection influence values from large to small, and the sorted arrangement sequence of the road elements in the traffic unit is determined as the recovery sequence for recovering the road elements in the traffic unit in the road traffic network.

The second recovery order determination method:

in this way, two parameter values, namely a network connection value and a connection influence value, in each road element in the traffic unit are obtained, the road elements in the traffic unit can be sorted according to the priority of the parameter values and the size of the parameter values, and the recovery sequence of the road elements in the traffic unit is determined according to the sorted sequence of the road elements in the traffic unit.

Specifically, in the embodiment of the present application, it is assumed that the priority of the network connectivity value is higher than the connectivity influence value, and if the network connectivity value and the connectivity influence value of each road element of one traffic unit are obtained, the road elements in the traffic unit may be first sorted according to the descending order of the network connectivity values; because the network connectivity values of different road elements may be the same, the road elements with the same network connectivity values may be sorted at the same position, and then after the first sorting, according to the sequence of the connectivity impact values from large to small, the road elements at the same position after the first sorting may be sorted for the second time, and the arrangement sequence of the road elements in the traffic network after the second sorting is determined as the recovery sequence for recovering the road elements in the traffic unit in the traffic network.

As an embodiment, after a traffic unit including the K road elements fails, a recovery sequence of the K road elements in the traffic unit may be determined through multiple rounds of recovery sequence determination processes, where in each round of recovery sequence determination processes, a simulation recovery is performed on the road elements whose recovery sequences have been determined in the recovery sequence determination processes before the round of recovery sequence determination processes, and then a recovery sequence of a road element whose recovery sequence is not determined in the K road elements is determined based on a road traffic network after the simulation recovery, and specific processes may refer to a third recovery sequence determination manner and a fourth recovery sequence process described below.

The third recovery order determination method:

in the method, the network connection value of each road element in the traffic unit is obtained, or the connection influence value of each road element in the traffic unit is obtained, and then the recovery sequence of K road elements in the traffic unit is determined according to one obtained parameter value of each road element.

Specifically, referring to fig. 9, for the K road elements in the traffic unit, the restoration order of each road element in the K road elements is determined through a multi-round restoration order determination process, where the i-th round restoration order determination process includes the following processes from step S1 to step S4, where i is a positive integer smaller than K:

step S1: and performing simulation recovery on the road elements with the determined recovery sequence in the K road elements in the road traffic network.

The simulation recovery is performed, that is, the road elements with the determined recovery sequence are set to be effective in the road traffic network.

Step S2: and determining the parameter value of the road element with the undetermined recovery sequence in the K road elements based on the road traffic network after the simulation recovery.

Step S3: and sorting the road elements of which the recovery sequence is not determined in the K road elements according to the sequence of the parameter values from large to small.

It should be noted that the above-mentioned first rank in step S4 is the rank-ordering position of the road element whose parameter value is the largest among the above-mentioned parameter values, and since there may be a plurality of road elements whose parameter values are the largest among the K road elements, the above-mentioned one-round restoration order determination process may determine the restoration orders of the plurality of road elements, and the restoration orders of the plurality of road elements determined by the one-round restoration order determination process are the same restoration order.

It should be noted that if i is 1, steps S1-S4 are 1 st round recovery order determination procedure, and since there is no road element for which the recovery order has been determined in the 1 st round recovery order determination procedure, step S1 may be omitted, and step S2 may be performed by determining the one parameter value for each of the K road elements based on the road traffic network after the traffic element failure, and then performing steps S3 and S4 to determine the 1 st recovered road element among the K road elements.

If only one road element of the K road elements, for which the restoration order is not determined, remains after the ith restored road element of the K road elements is determined in the ith round of restoration order determination process, the restoration order of only the remaining road element may be directly determined as the (i + 1) th restoration of the K road elements without performing the (i + 1) th round of restoration order determination process.

The fourth recovery order determination method:

in the method, the network connection value and the connection influence value of each road element in the traffic unit are obtained, and then the recovery sequence of K road elements in the traffic unit is determined according to the two obtained parameter values of each road element.

Specifically, please refer to fig. 10, for the K road elements in the traffic unit, a recovery order of each road element in the K road elements is determined through the following multi-round recovery order determination process; wherein the j-th round recovery order determination process includes the following processes of step S11 to step S14, where j is a positive integer smaller than K:

step S11: and performing simulation recovery on the road elements with the determined recovery sequence in the K road elements in the road traffic network.

Step S12: and determining the two parameter values of the road elements of which the recovery sequence is not determined in the K road elements based on the road traffic network subjected to simulation recovery.

Namely, the network connectivity value and the connectivity influence value of each road element for which the restoration order is not determined are determined separately in this step.

Step S13: and according to the sequence of the parameter value with high priority in the two parameter values from large to small, carrying out first sequencing on the road elements which are not determined to restore the sequence in the K road elements.

The network connectivity value and the connectivity influence value priority are not limited too much, and those skilled in the art can set the network connectivity value and the connectivity influence value according to actual requirements, for example, the network connectivity value and the connectivity influence value priority are set as follows: the priority of the network connectivity value is higher than the priority of the connectivity impact value, or the priority is set to: the connectivity impact value has a higher priority than the network connectivity value.

Step S14: determining the recovery sequence of the road elements which are sorted in the first sequence and are unique in the first-time sorted road elements as the jth recovery of the K road elements; if the road elements sorted in the first sequence in the road elements sorted in the first sequence comprise at least two road elements, sorting the at least two road elements for the second time according to the sequence of the parameter values with low priority from large to small in the two parameter values, and determining the recovery sequence of the road elements sorted in the first sequence in the road elements sorted in the second sequence as the jth recovery in the K road elements.

It should be noted that, the first rank after the first sorting is the sorting position of the road element with the largest parameter value among the parameter values with high priority, and since there may be a plurality of road elements with the largest parameter value among the parameters with high priority among the K road elements, there may be a plurality of road elements sorted in the first rank among the road elements sorted in the first sorting, it is necessary to distinguish the importance of the road elements sorted in the first rank after the first sorting based on the size of the parameter value with low priority of the plurality of road elements in the first rank.

The second sorting is carried out on the road elements sorted in the first sequence after the first sorting based on the size of the parameter value with low priority, and a plurality of road elements sorted in the first sequence in the road elements sorted in the second sorting still can be available; in this case, the recovery order of the road elements sorted in the first rank after the second sorting may be determined as the jth recovery of the K road elements; or according to other indexes of the road traffic network of the plurality of road elements sorted in the first ordinal after the second sorting, re-sorting the plurality of road elements sorted in the first ordinal after the second sorting until a unique road element can be determined from the plurality of road elements sorted in the first ordinal after the second sorting, and determining the recovery sequence of the determined unique road element as the jth recovery of the K road elements.

It should be noted that if j is 1, steps S11-S14 are 1 st round recovery order determination procedure, and since there is no road element for which the recovery order has been determined in the 1 st round recovery order determination procedure, step S11 may be omitted, and directly in step S12, two parameter values of each road element of the K road elements are determined based on the road traffic network after the traffic element failure, and then steps S13 and S41 are performed to determine the 1 st recovered road element of the K road elements.

If only one road element of the K road elements is left after the jth restored road element of the K road elements is determined in the jth round of restoration order determination process, the j +1 th round of restoration order determination process is not needed, and the restoration order of only the remaining road element can be directly determined as the j +1 th restoration of the K road elements.

Here, a simulation effect diagram of an attack on a traffic unit including a plurality of road elements is given, please refer to fig. 11, the attack on the traffic unit including node 1, node 3, node 7, node 8, node 11, node 12, node 19, node 22, node 23, node 24, node 25, node 27, node 28, node 29, node 30 and node 32 results in that links around the 16 nodes and the 16 nodes are affected when the attack on the traffic unit is performed, the simulation result shows that 61.25% of nodes in the road traffic network are not connected after the attack on the traffic unit is failed, the network efficiency is also reduced to 0.13, and the number of the affected nodes which are not connected is 47.41%; and after attacking the traffic unit, determining a recovery sequence for recovering each road element in the traffic unit in the road traffic network according to the second recovery sequence determination mode, wherein the specific recovery sequence is shown in fig. 12.

According to the scheme provided by the embodiment of the application, the weak units in the road traffic network can be identified according to the network communication value of each traffic unit in the road traffic network, so that the weak units can be protected at a later stage or can be quickly recovered after being attacked; in addition, in the embodiment of the application, the vulnerability degree of the road traffic network can be determined according to the identified weak units, and after the traffic unit containing a plurality of road elements fails, the recovery sequence of each road element in the failed traffic unit is determined, so that the recovery speed of the road traffic network in the face of an emergency attack event is accelerated.

Referring to fig. 13, based on the same inventive concept, an embodiment of the present application provides an apparatus 1300 for identifying a weak cell in a road traffic network, including:

a traffic unit obtaining unit 1301, configured to extract each traffic unit in a road traffic network by setting a communication interface, where the traffic unit includes a node in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying a connecting edge connecting the node, and the node represents an end point of a road or an intersection of at least two roads;

A network connectivity value determining unit 1302, configured to determine a network connectivity value of each traffic unit, where the network connectivity value is determined by identifying a node pair that is disconnected due to failure of each traffic unit; the node pair comprises a set formed by any two nodes with passing paths in the road traffic network;

and a weak cell identification unit 1303, configured to identify a weak cell in the traffic cells according to the network connectivity value and the connectivity value threshold of each traffic cell, where the weak cell includes a traffic cell having a high influence on the connectivity degree of the road traffic network.

As an example, the apparatus 1300 further includes:

a network vulnerability determining unit 1304, configured to determine a vulnerability of the road traffic network according to at least one information of the number of identified weak cells and a communication influence value of the weak cells on the road traffic network; the connection influence value is obtained by identifying at least one of a change value of the network efficiency of the road traffic network caused by the failure of the weak cell and information of a node pair which is not connected.

As an embodiment, the traffic unit includes nodes in the road traffic network and K road elements in a traffic path, where K is a positive integer greater than 1, and the apparatus 1300 further includes:

A network recovery unit 1305, configured to, if the traffic unit fails, obtain at least one parameter value of a network connectivity value and a connectivity influence value of each road element in the traffic unit, where the connectivity influence value is obtained by identifying at least one of a change value of network efficiency of the road traffic network caused by the failure of each road element and information of a node pair that is not connected;

As an embodiment, the network recovery unit 1305 is specifically configured to:

if a parameter value of each road element in the traffic unit is obtained, sorting each road element in the traffic unit according to the size of the parameter value; otherwise, sorting the road elements in the traffic unit according to the priority of each parameter value in the at least one parameter value and the size of the parameter value;

and determining the sequence of the road elements in the sequenced traffic units as a recovery sequence for recovering the road elements in the traffic units in the road traffic network.

As an embodiment, the network recovering unit 1305 is specifically configured to obtain a parameter value of each road element in the traffic unit, and determine, for the K road elements in the traffic unit, a recovering order of each road element in the K road elements through the following multiple-round recovering order determining processes, where the recovering order determining process of the ith round includes the following processes from step S1 to step S4, and i is a positive integer smaller than K:

step S1: performing simulation restoration on the road elements with the determined restoration sequence in the K road elements in the road traffic network;

step S2: determining the one parameter value of the road element with the undetermined recovery sequence in the K road elements based on the road traffic network subjected to simulation recovery;

step S3: according to the sequence of the parameter values from large to small, sorting the road elements which are not determined to be in the recovery sequence in the K road elements;

As an embodiment, the network recovering unit 1305 is specifically configured to obtain two parameter values of each road element in the traffic unit, and determine, for the K road elements in the traffic unit, a recovering order of each road element in the K road elements through the following multiple-round recovering order determining processes, where the j-th-round recovering order determining process includes the following processes from step S11 to step S14, and j is a positive integer smaller than K:

Step S11: performing simulation recovery on road elements with a determined recovery sequence in K road elements in a road traffic network;

As an embodiment, the network connectivity value is a ratio of the number of connected node pairs in the road traffic network to the total number of node pairs in the road traffic network after each traffic unit fails, and the weak unit is a traffic unit of which the network connectivity value is smaller than a first connectivity value threshold; or

The network connectivity value is a ratio of the number of the non-connected node pairs in the road traffic network to the total number of the node pairs in the road traffic network after each traffic unit fails, and the weak unit is a traffic unit of which the network connectivity value is smaller than a second connectivity threshold value.

As an embodiment, the network efficiency includes an average value of reference path values of node pairs in the road traffic network, where the reference path value is an inverse number of a shortest traffic path corresponding to the node pairs.

spatial distribution information of disconnected node pairs.

As an example, the apparatus in fig. 13 may be used to implement any of the methods discussed above for identifying weak cells in a road traffic network.

As shown in fig. 14, the present application provides a computer device 1400 comprising a processor 1401, a memory 1402 for storing processor-executable instructions as described above;

wherein the processor is configured to execute executable instructions to implement any of the above methods for identifying a weak cell in a road traffic network.

In an exemplary embodiment, a storage medium comprising instructions, such as a memory comprising instructions, executable by a processor of the electronic device to perform the method is also provided. Alternatively, the storage medium may be a non-transitory computer readable storage medium, for example, which may be a ROM, a Random Access Memory (RAM), a CD-ROM, a magnetic tape, a floppy disk, an optical data storage device, and the like.

As will be appreciated by one skilled in the art, embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

Claims

1. A method of identifying a weak cell in a road traffic network, comprising:

2. The method of claim 1, further comprising:

3. The method of claim 1, wherein the traffic unit includes nodes in the road traffic network and K road elements in a transit path, K being a positive integer greater than 1, further comprising:

4. The method of claim 3, wherein obtaining a parameter value for each road element in the traffic element, and determining a recovery order in the road traffic network for recovering each road element in the traffic element based on the obtained at least one parameter value for each road element in the traffic element comprises:

5. The method of claim 3, wherein two parameter values are obtained for each road element in the traffic unit, the two parameter values including the network connectivity value and the connectivity impact value, and wherein determining the order of restoration in the road traffic network for restoring each road element in the traffic unit based on the obtained at least one parameter value for each road element in the traffic unit comprises:

6. The method of any one of claims 1-4, wherein the network connectivity value is a ratio of a number of pairs of nodes in the road traffic network that are connected after failure of each traffic cell to a total number of pairs of nodes in the road traffic network, and the weak cells are traffic cells having a network connectivity value less than a first connectivity value threshold; or

7. The method of any of claims 1-4, wherein the information of the disconnected node pairs comprises one or more of:

spatial distribution information of disconnected node pairs.

8. An apparatus for identifying weak cells in a road traffic network, comprising:

the traffic unit acquisition unit is used for extracting a network communication value of each traffic unit in a road traffic network by setting a communication interface, wherein each traffic unit comprises a node in the road traffic network and at least one road element in a passing path, the passing path is obtained by identifying a connecting edge connecting the nodes, and the nodes represent end points of the road or intersections of at least two roads;

9. A computer device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, characterized in that the steps of the method of any of claims 1-7 are implemented when the program is executed by the processor.

10. A computer-readable storage medium having stored thereon computer instructions which, when executed on a computer, cause the computer to perform the method of any one of claims 1-7.